Si/Ge Quantum Wells

- Quantum Well structures are formed by manipulating the strain and bandgap of semiconductor materials.
- 2-dimensional electron gas (2DEG) structures can be formed in a tensile strained silicon channel grown on relaxed SiGe.
- 2-dimensioanl hole gas (2DHG) structures can be formed in a compressively strained germanium channel grown on relaxed SiGe.
- Both structures offer extremely high levels of carrier mobility due to various effects such as modulation doping, strain and carrier confinement.
- Quantum Well structures have various applications where high mobilities are required such as in CMOS, spintronics or terahertz detectors.

2DEG/2DHG Growth

- Advanced Epi can develop and grow both Si or Ge Quantum Well structures on wafer diameters up to 200mm diameter.
- In depth calibration of each epilayer thickness, strain state, crystal quality and doping is used to optimise the carrier mobility up to values of ~2,000,000 cm2/Vs at low temperature.

Heterostructures

Silicon Quantum Well Structure

Left - Typical silicon Quantum Well (2DEG) heterostructure

Right - Typical germanium Quantum Well (2DHG) heterostructure

Ge QW